12.9.Â Respect CFLAGS

The port must respect CFLAGS.
What we mean by this is that the port must not set
the value of this variable absolutely, overriding the existing
value. Instead, it may append whatever values it needs to the
existing value. This is so that build options that affect all
ports can be set globally.

If it does not, please add
NO_PACKAGE=ignores cflags to the
Makefile.

Here is an example of a Makefile
respecting CFLAGS. Note the
+=:

CFLAGS+= -Wall -Werror

Here is an example which does not respect
CFLAGS:

CFLAGS= -Wall -Werror

CFLAGS is defined on
FreeBSD systems in /etc/make.conf. The first
example appends additional flags to
CFLAGS, preserving any system-wide
definitions. The second example clobbers anything previously
defined.

Remove optimization flags from the third party
Makefiles. The system
CFLAGS contains system-wide optimization
flags. An example from an unmodified
Makefile:

CFLAGS= -O3 -funroll-loops -DHAVE_SOUND

Using system optimization flags, the
Makefile would look similar to this
example: